Daylight developing tank for roll film



Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE DAYLIGHT DEVELOPINGTANK FOR ROLL FILM 1 Claim.

This invention relates to photographic equipment, and more particularlyto a tank for use in developing film.

The object of the invention is to provide a tank which will facilitatethe development of roll film, the tank being constructed so that thefilm can be developed during daylight.

Another object of the invention is to provide a film developing tankwhich is adapted to receive the film after it has been unwound from thespool, the film extending longitudinally through the tank whereby theentire film is developed simultaneously by the fluid or solution in thetank.

Still another object of the invention is to provide a developing tankwhich includes film supporting posts whose position can be adjusted inthe tank whereby films of various sizes and lengths are being developed.

A further object of the invention is to provide a film developing tankwhich is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are used to designate like parts throughout thesame:

Figure l is a front elevational View of the film developing tank,according to the present invention;

Figure 2 is a top plan view of the tank;

Figure 3 is a sectional view taken on the line 3-3 of Figure 5;

Figure 4 is a sectional view taken on the line 4-4 of Figure 5;

Figure 5 is an enlarged sectional view taken on the line 55 of Figure 6;

Figure 6 is a sectional view taken on the line B-6 of Figure 5;

Figure 7 is a view showing certain constructional details of the tank;and

Figure 8 is a sectional view taken on the line 8-8 of Figure 5.

Referring in detail to the drawings, there is shown a tank fordeveloping film and the tank includes a bottom wall [0, and projectingfrom the bottom wall and secured thereto is a pair of spaced sidewalls Hand I2. The sidewalls II and I2 of the tank are of arcuate formation andhave their convex faces facing inwardly as best seen in Figure so that aminimum quantity of developing solution will be required to fill thetank in order to develop the film strip. The tank further includesspaced parallel end walls l3 and I4 which are arranged between thesidewalls Ii and I2 and are secured thereto.

A cover or lid 15 is mounted for movement into and out of closingrelation with respect to the top of the tank, there being a plurality ofhinges I6 for hingedly connecting the cover IE to the upper end of thesidewall [2. A sealing means i provided for insuring that no lightenters between the cover l5 and the walls of the tank and further, thissealing means serves to prevent any accidental loss of fluid from thetank when the tank is being agitated. This sealing means comprises arectangular body member I"! which extends around the inner surfaces ofthe sidewalls and end walls and is secured thereto. The body member ITis arranged adjacent the top of the tank and coacting with the bodymember I"! is a second body member l8 which is rectangular in shapealso. The body member [8 is secured to the inner or lower surface of thecover l5 and is of such a size so as to snugly seat between thesidewalls and endwalls of the tank when the cover is in closed positionon the tank, to thereby provide a fluid tight seal between the cover andtank.

The cover [5 carries an inlet means whereby the tank can be filled withsuitable fluid and this inlet means has a trap 4 associated therewith sothat light will be prevented from entering the tank. This inlet meanscomprises a support member [9 which is provided with an oval shapedopening or port 20 for the ingress therethrough of suitable fluid. Thesupport member IS includes a pair of spaced parallel legs 2| and 22which have secured to their lower ends a fiat plate member 23, Figure 5.Suitable blocks 24 and 24, Figure 7, extend between the lower or innersurface of the cover [5 and the upper surface of the plate member 23 andare secured thereto. Arranged adjacent one end of the plate member 23and extending between the cover l5 and plate member 23 is a pair ofL-shaped members 25, there being a similar pair of members 26 extendingbetween the other end of the plate member 23 and the cover 15. Thus,fluid entering the tank passes through the opening 20, and then passesthrough the space between the legs 2i and 22 and out through the spacebetween the spacer blocks 25 or 26 or out through openings 6 in theplate member 23. Thus, the fluid will follow a tortuous path through thetrap so that light will be prevented from entering the interior of thetank.

Arranged in the tank and supported on the bottom wall In is a pair ofblocks 21 and 28,

3 Figure 6. The blocks 21 and 28 are each tapered or sloped downwardlytowards the center of the tank so that a well is formed centrally in thetank.

Each of the blocks 21 and 28 is provided with a plurality of openings29, the openings being arranged in pairs, for receiving therein thelower ends of dowel posts or pins 30. Each of the dowel posts 30includes a lower vertical section 3| which is arranged in engagementwith the proper opening 29, and the dowel post further includes an upperinclined section 32. In use, each of the dowel posts 30 are arranged sothat a pair of the dowel posts project from each of the blocks 21 and 28and the dowel posts provide a space therebetween. Then, the film strip33, which is to be developed, is inserted in the space between the dowelposts 30. Since the upper section 32 of the dowel post 30 diverges or isinclined outwardly, the insertion of the film strip 33 in the spacebetween the coacting dowel posts will be facilitated. A tapered clip 34is arranged in engagement with each of the free ends of the film strip33 and the clips 34 abuts the corresponding dowel posts to maintain thefilm strip 33 stretched longitudinally in the tank.

Further, an outlet means is provided for the discharge or egresstherethrough of the fluid from the tank and the outlet means is providedwith a trap to prevent light from entering the tank. This outlet meansis designated generally by the numeral 8 and the outlet means comprisesa support member 35 which is provided with an oval shaped opening orvent 36 for the discharge therethrough of fluid, the opening 36registering with an opening 31, Figure 5, in the sidewall H. The trap 5includes an arcuate plate member 38 which is spaced from the innersurface of the sidewall II and a pair of blocks 39 and 40 extend betweenthe sidewall H and plate member 38 and are secured thereto. Further, alight stop 4| is arranged transversely with respect to the members 33and 40 and the member 41 coacts with a pair of members 42 and 43 todefine a tortuous path for the fluid leaving the tank. Thus, the trap 4and 5 insures that no light will accidentally enter the interior of thetank [0.

Further, the developing tank is provided with a latch 44, Figure 1, andthe latch 44 serves to maintain the cover in its closed position asdesired, in order to prevent accidental opening of the cover l5.

From the foregoing, it is apparent that a tank has been provided whichis especially suitable for use in developing roll film. The tank can beused for developing such film during the daylight, since the tank isconstructed so as to prevent any light from accidentally entering thetank and destroying the film being developed therein. Thus, in use, thefilm strip 33 is unwound from its spool and the film strip 33 isextended longitudinally in the tank. One end of the film strip 33 isinterposed between one pair of the dowel pins 30, while the other end ofthe film strip 33 is positioned between the other pair of dowel posts30. Then, the clip 34 is arranged in engagement with each end of thefilm strip 33 in order to maintain the film strip stretchedlongitudinally in the tank. Suitable fluid can be placed in the tankthrough the inlet opening 20. Further, when fluid is to be retained inthe tank, a suitable plug may be used to close the opening 36, and whenthe fiuid is to be discharged from the tank, the plug can be removedfrom the opening 36 to permit the discharge therethrough of the fluid.Also, film strips 33 of various lengths can be supported in the tank.Thus, the dowel posts 30 can be positioned in the proper openings 29whereupon the distance between the complementary pairs of dowel postscan be varied as desired. Also, the openings 30 and 36 need notnecessarily have an oval shape, and in lieu of using a plug to close theopenings 36, a conventional outlet faucet may be substituted. Theopening 20 can also receive the discharge end of a funnel to facilitatethe filling of the tank.

What I claim:

A device for developing film, comprising a bottom wall, end wallsprojecting from said bottom wall and secured thereto, a pair of spacedside walls projecting from said bottom wall and secured thereto, saidside walls being of arcuate formation with their convex faces facinginwardly, a cover hingedly connected to one of said side walls, a firstbody member secured to the inner surface of said end and side walls andarranged adjacent the upper ends thereof, a second body member securedto the inner surface of said cover and coacting with said first bodymember to provide a fiuidtight seal when the cover is closed on saidtank, inlet means on said cover for filling said tank with fluid, outletmeans for discharging fiuid from said tank, a latch for preventingaccidental opening of said cover, a pair of blocks secured to the innersurface of said bottom wall, said blocks being tapered to define a wellintermediate the ends of said tank, a pair of spaced coacting postsadjustably supported by each of said blocks for supporting a roll offilm in said tank, said dowel posts having a lower vertical section andan upper inclined section to facilitate the insertion of the filmbetween said posts.

LEONARD H. HARRISON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 907,942 Zierath Dec. 29, 1908951,983 Center Mar. 15, 1910 1,130,152 Davis Mar. 2, 1915 FOREIGNPATENTS Number Country Date 567,200 Great Britain Feb. 1, 1945

